ITP/OCL: A rewriting-based validation tool for UML+OCL static class diagrams. In this paper we present the ITP/OCL tool, a rewriting-based tool that supports automatic validation of UML class diagrams with respect to OCL constraints. Its implementation is directly based on the equational specification of UML+OCL class diagrams. It is written entirely in Maude making extensive use of its reflective capabilities. We also give notice of the Visual ITP/OCL, a Java graphical interface that can be used as a front-end for the ITP/OCL tool.